CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 78,765	$ 196,746	$ 269,601	$ 401,573
Other comprehensive income (loss) - net unrealized gain (loss) on cash flow hedging derivatives, net of income tax	186	(52)	223	(223)
Comprehensive income	78,951	196,694	269,824	401,350
Comprehensive income attributable to noncontrolling interests	(3,269)	(2,444)	(6,765)	(2,943)
Comprehensive income attributable to Steel Dynamics, Inc.	$ 75,682	$ 194,250	$ 263,059	$ 398,407